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Infectious Mononucleousis (Mono)

Mononukleose (Latin name)

By Bjarne Lühr Hansen PhD, MD and Philipp Skafte-Holm MD, Mentor Institute

Mono is caused by a viral infection and appears especially with children less than 5 years old. Far most parents do not even know that their child has mono because the child does not become particularly ill. Typically, mono resembles common cold with a little fever and complaints about a sore throat. Mono is untreatable.

Mono is a viral infection. Especially, children less than 5 years old have mono. In the age of 5 to 15 years mono is rare. Half of all children who have turned 5 years have already had mono and usually without the parents discovering it. The child can only contract the illness once in a lifetime.

The symptoms of mono stretch from common cold to severe tonsillitis. Ordinarily, mono appears as a common cold. The child complains about a sore throat and its temperature rises slightly. In this case, the illness lasts for 1 week.

In rare cases, the child becomes more ill with higher fever, strong pains in the throat and swollen lymph glands. The fever is about 39-40°C and can last up to 3 weeks. Pronounced pain associated with swallowing makes it hard for the child to eat and difficult to drink.

The swollen lymph nodes can feel like sore lumps the size of peas on the neck and sometimes in the armpit and the groin area. If you look into the child’s mouth, you can see that the tonsils are large with white coating. A few children develop a large rash of red spots on the chest.

To find out whether the child has mono, it is necessary to take a blood sample. The child needs to have been ill for 1 week before you take the blood sample.

Complications, seen with teenagers and young adults, practically never occur with children. The most feared complication is that the tonsils swell so much that the child has trouble breathing.

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The illness infects through spit and can be transferred to the child by kiss. Toys and cups for drinking containing spit can transfer the illness. A child with mono can infect other children up to several months after the illness has started. It takes between 3 to 8 weeks from the child is infected till it falls ill.

Day care:
The child can attend day care when it has fully recovered. This means that the child can participate in its usual activities without extra care.


Ordinary painkillers and antipyretics (paracetamol) can soothe.

What can you do?

Mono is untreatable – it disappears on its own. If the child has a fever, it should have plenty to drink and stay in a cool room without too much clothes on.

Contact the doctor tomorrow

If you suspect mono.

Contact the doctor immediately

If the child has trouble breathing.